In a conventional air-conditioning system, a controller and an air-conditioning apparatus including an indoor unit and an outdoor unit are interconnected via a common bus and thereby allowed to exchange various information with each other. The common bus interconnecting the air-conditioning apparatus and the controller is an example of a medium used to conduct communications, and various media can be applied to the communications, regardless of whether they are each wired or wireless.
Also, in some conventional air-conditioning systems, each of air-conditioning apparatuses forming the system is provided with a controller (see, for example, Patent Literature 1). Where controllers are connected in a system as in the air-conditioning system described in Patent Literature 1, for example, a master control unit of the controller having the highest capacity functions as an upper-level master control unit, and assigns control units to lower-level master control units. Also, to control the air-conditioning apparatuses in the respective controllers, virtual control units are produced by the master control units.
By virtue of the above, it is possible to easily and efficiently produce the virtual control units even if controllers are connected in an air-conditioning system.
To install an additional air-conditioning apparatus and controller in such an air-conditioning system, a mechanism for installing and connecting the additional air-conditioning apparatus and controller via a common bus connected with existing air-conditioning apparatuses and controllers has been proposed.